Peel Off the Pounds Faster

If you're about to start a diet  or wondering why the one you're on isn't working  our true/false quiz will set you on the slim and narrow

1. To lose a pound, you must cut 3,500 calories

FALSE This much-quoted equation doesn't account for the slowdown that happens to your metabolism as you drop pounds, explain researchers at the National Institutes of Health. "As a result, it drastically overestimates how quickly people will lose weight," says senior investigator Kevin D. Hall, Ph.D. That's why his team has created a new, computerized model that accurately predicts just how long you'll have to say non to french fries. It takes into consideration not only the drop in calorie burn as you get slimmer, but also your current weight, your age, how much you're eating now, and other variables.

Let's say you're a 46-year-old woman who weighs 170 pounds. According to the traditional formula, if you cut 500 calories a day, you would drop a pound a week (500 ≈ 7 days = 3,500 calories, or 1 pound)  and lose 26 pounds in six months. But the new math shows that the weight loss is more likely to be 19.5 pounds.

Make this work for you The weight-loss gods may be cruel, but knowing what to expect can keep you from getting discouraged  and from backsliding  when the scale seems stuck. To try the new Body Weight Simulator, go to bwsimulator.niddk.nih.gov. Especially cool: You can vary predictions of how much you might lose and how long it will take by changing what you plug in for your calorie intake and exercise level.

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